The S550 Mustang GT's 5.0L Coyote is one of the best-sounding naturally aspirated V8s Ford has produced — but the factory exhaust chokes it. Whether you're running active valve delete, chasing that open-throated V8 bark at wide-open throttle, or just done with the muffled stock note at idle, a cat-back is the highest-impact bolt-on for this platform. What separates the right system from the wrong one: tip finish to match your build, valve compatibility with your specific model year and transmission combo, and sound character — because S-Type (aggressive but livable) and ATAK (loud, no compromise) are genuinely different products built for different owners.
Quick links
- 1. Borla S-Type Cat-Back (No Valves, Polished Tips)
- 2. Borla ATAK Cat-Back (No Valves, Polished Tips)
- 3. Roush Cat-Back Exhaust Kit (Fastback Only)
- 4. Borla S-Type Cat-Back (With Valves)
- 5. Borla ATAK Cat-Back (With Valves)
- 6. AWE Touring Edition Cat-Back (Diamond Black Tips)
- 7. Corsa 3in Cat-Back (Polished Tips)
- How to choose a cat-back for the Mustang GT
- FAQ
1. Borla S-Type Cat-Back (No Valves, Polished Tips) — 140745
The S-Type is Borla's most popular street tune for good reason: it's aggressive enough to remind you the Coyote is a V8 at every throttle blip, but it won't drone your eardrums out on a two-hour highway run. The 3-inch diameter tubing flows well past stock power levels and leaves headroom for cams or forced induction later. This specific SKU is for non-valve-equipped models — if your GT didn't come with active exhaust from the factory, this is your clean, no-adapter starting point with polished quad tips.
Borla S-Type Cat-Back (No Valves, Polished) — 140745 — $2037
2. Borla ATAK Cat-Back (No Valves, Polished Tips) — 140746
ATAK stands for Acoustically Tuned Aggressive Krafted — and Borla isn't being subtle. This system runs significantly louder than the S-Type at every RPM, with a raw, high-pitched Coyote wail under hard acceleration that forum builds consistently describe as the loudest street-legal option in the Borla lineup. Not drone-free on every freeway speed, but if you're building a weekend/track car or a daily where volume is a feature rather than a liability, this is the pick. Same 3-inch pipe, same no-valve fitment as the 140745 above.
Borla ATAK Cat-Back (No Valves, Polished) — 140746 — $2136
3. Roush Cat-Back Exhaust Kit (Fastback Only) — 422093
Roush has been building Mustang-specific performance parts longer than most tuner brands have existed, and this kit reflects that. It's engineered specifically for the Fastback body — convertible owners, look elsewhere. The tone sits between an S-Type and ATAK in character: distinctly American muscle, full at idle, and sharp at the top end without the rasp some ATAK owners report post-cam. At $1579 it's also the most accessible system in this lineup, which makes it a strong entry point for a first bolt-on before cams or a tune changes the equation.
Roush Cat-Back Exhaust Kit (Fastback Only) — 422093 — $1579
4. Borla S-Type Cat-Back (With Valves) — 140742
If your S550 GT came factory-equipped with active exhaust valves, this is the S-Type build for your car. It retains full OEM valve functionality — quiet mode is actually quiet, and the transition to open mode under throttle is immediate and satisfying. The S-Type character remains unchanged from 140745, but with the added daily-driver usability that makes this system genuinely work in both modes. Worth the premium over the no-valve version if you're keeping the stock PCM valve control intact.
Borla S-Type Cat-Back (With Valves) — 140742 — $2569
5. Borla ATAK Cat-Back (With Valves) — 140743
The ATAK with active valve support is the most versatile loud build in this guide. You get the full aggressive ATAK character at WOT and on spirited drives, with the valve system genuinely taming idle and low-RPM noise in quiet mode — something that matters if you live in a neighborhood with thin walls and a 6 AM start time. Builds on MustangForums running this specific setup consistently note it as the top pick for owners who want maximum sound potential without committing to loud 24/7. The price reflects the added valve hardware.
Borla ATAK Cat-Back (With Valves) — 140743 — $2669
6. AWE Touring Edition Cat-Back (Quad Diamond Black Tips) — 3015-43106
AWE's Touring Edition splits the difference between the Borla S-Type and ATAK in terms of character — refined, not timid. The SwitchPath-ready design means if you ever add AWE's active control module, you can run a true dual-mode setup. The quad diamond black tips are a standout detail on darker Mustang colors and don't carry the upcharge you'd pay for Borla's black chrome variants. If you're pairing this exhaust with a wheel upgrade and want the visual language to be cohesive — dark tips against a dark lip or face — this is the system that earns that aesthetic.
AWE Touring Edition Cat-Back (Diamond Black Tips) — 3015-43106 — $2200
7. Corsa 3in Cat-Back Dual Rear Exit (Polished Tips) — 21040
Corsa builds around their Reflective Sound Cancellation (RSC) technology, which targets drone frequencies specifically rather than just muffling overall volume. The result is a system that can run louder than a stock exhaust while producing less interior drone at highway cruise than most competitors — a claim that holds up in back-to-back tests documented by multiple S550 owners on YouTube. The 4-inch polished Pro-Series tips are aggressively sized and the dual rear exit routing is clean. Note: this SKU is confirmed fitment for 2018-2019 model years.
Corsa Cat-Back Dual Rear Exit (Polished Tips) — 21040 — $2100
How to choose a cat-back for the Mustang GT (2018-2023)
Valve or no valve? This is the first decision, not sound character. S550 GTs with the factory active exhaust option require valve-compatible systems (Borla 140742 or 140743 series) unless you're deleting the valves entirely and blocking off the OEM actuator connections. Running a no-valve system on a valve-equipped car without proper deletion hardware creates drone paths and potential exhaust leaks at the junction points.
S-Type vs ATAK vs Roush vs Corsa vs AWE: S-Type is the daily-friendly aggressive. ATAK is weekend/track loud with no meaningful drone compromise. Roush sits tonally between the two with a more traditional muscle car character. Corsa's RSC technology is the play if drone is your primary concern. AWE Touring is the pick when aesthetics and SwitchPath compatibility matter as much as sound.
Fastback vs Convertible: The Roush 422093 is explicitly Fastback-only. All Borla SKUs listed here fit both body styles with matching valve/no-valve configuration. Always confirm body style before ordering.
Tip finish: Polished tips read as traditional performance. Black chrome and diamond black tips suit blacked-out builds and pair cleanly with dark aftermarket wheels. Both Borla and Corsa offer black tip variants; AWE's black tips are standard on this SKU. If you're running a two-tone or dark wheel setup, tip matching matters more than people acknowledge before seeing it in person.
Downstream mods: All 3-inch systems listed here flow beyond what a stock-tune Coyote can use. If you're planning cams, supercharger, or E85 conversion, the exhaust you buy today won't be the bottleneck. Buy based on sound and fitment, not flow numbers at stock power levels.
If you're also considering suspension work alongside your exhaust build, our suspension category covers coilovers and spring options. For wheel fitment reference on the S650 platform, see our S650 Mustang GT deep-dive. And if drag strip use is part of the plan, our drag radials vs street tires guide pairs directly with an exhaust-forward build strategy.
FAQ
Do I need a tune after installing a cat-back exhaust on the 2018-2023 Mustang GT?
No. A cat-back system replaces only the post-cat section of the exhaust — it doesn't affect oxygen sensor placement or air/fuel metering. The Coyote's PCM will run normally without a retune. A tune becomes relevant when you add headers (which affect pre-cat O2 sensors) or when you're combining exhaust with intake, cams, or forced induction.
Will Borla no-valve systems work on my active exhaust GT?
They can physically bolt on, but you'll need to properly delete or cap the OEM valve actuator connections to avoid exhaust leaks and valve flutter at the junction. The cleaner solution is to run the appropriate valve-compatible SKU (140742 for S-Type, 140743 for ATAK) which integrates with your factory system. If you want to delete active valves entirely, that's a separate procedure requiring actuator blocking and potentially PCM reflash to suppress error codes.
What's the confirmed fitment range — does this cover 2020-2023 Mustang GTs?
All Borla systems listed (140742, 140743, 140745, 140746 and their BC variants) are listed as 2018-fitment but are confirmed compatible with 2018-2023 S550 GT models as the platform architecture didn't change materially through that model run. The Roush 422093 explicitly covers 2018-2024. The Corsa 21040 and 21042BLK are confirmed for 2018-2019; for 2020-2023, verify with Corsa's fitment guide before ordering. AWE's 3015-43106 is listed as 2018+ and covers the full S550 generation.
Can I pair any of these exhausts with a wheel upgrade for a complete build?
Absolutely — exhaust and wheels are the two highest-visual-impact bolt-ons on the S550. For the Mustang GT, a staggered fitment on 19- or 20-inch wheels pairs well with any of the systems above. Browse our full wheel catalog or check our wheel accessories section for center caps, lug nuts, and hub hardware. The track vs street tire guide is worth reading if you're planning both upgrades simultaneously.